The benefits of exercising animals such as race horses in the water are well-known. When the exercise is given at an appropriate water depth, at least some of the horse's weight is taken off of the animal's legs, and the workout can provide the necessary exercise, but without as much effect on a lame leg, for example. Also, the race horse may be so saddle sore that it cannot be ridden. Then an appropriate workout can still be given to the horse, but without a rider.
Submerged treadmills for this purpose are shown in Scanlon U.S. Pat. No. 3,485,213 and Davis U.S. Pat. No. 4,332,217. The problems of limb support and of belt friction are discussed in Davis U.S. Pat. No. 4,227,487.
In the instant invention, the treadmill is disposed in a trench, and ramps lead from grade down to the treadmill so the animal can walk through the system without draining the pool. While on the treadmill the animal is restrained so as to remain in place, and must run or walk to keep up with the powered treadmill. The water remains in the pool, and is recirculated through pumping and filtration means.
Such a system has two problems. One relates to treadmill belt wear and down time, and the other to general sanitation and cleanliness of the system.
As to belt wear, the horse steps heavily on the belt, and the belt drags along a supporting plate. This type of wear destroys the belt in a rather short length of time. Treatment of horses with this system is quite profitable, and down time for repairs must be minimized.
As to sanitation, horses have no concept of it, and a pool in which horses exercise is soon contaminated with particulate fecal material. Unless something is done about this, horses will leave the tank covered with material, the tank will become foul, and during operation the mechanism can tend to gum up.
A technique which has been used to minimize this pollution is continuously to recycle the water through conventional filters such as are used in swimming pools or in water clarification plants. However, these very soon plug up due to the large amount of material deposited by the animals. Furthermore, even though during exercise the animal stirs the pool rather vigorously, it is practically impossible to get all the material through the filter in a sensibly short period of time. As a result, the conventional pool is too often an unsightly scene. Fastidious horse owners dislike it.
This invention attends to these problems, providing a cleaner and more quickly cleaned pool, and greatly extending the life of the treadmill belt.